Hmm.. I think its one of those names that changes its feel depending on middle names or sibling names. But for me River is all boy. I met this adorable little boy on the train a while back, who was commenting on the "ding-ers" (or the train crossing lights, haha.) His name was Miles and his little brother who was asleep on mum's lap was River. I say keep it on your list, to me its screams boy - in a good way But like most things to each their own.